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XX. The Influence of Stress and Strain on the Physical Properties of Matter. 
By Herbert Tomlinson, B.A. 
Communicated by Professor W. Grylls Adams, M.A., F.R.S. 
Received February 18,—Read March 11, 1886. 
(Revised by the Author October 19, 1886.) 
[Plate 43.] 
PART I.—ELASTICITT (continued). 
The Internal Friction of Metals. 
Origin and Purpose of the Investigation. 
I have already had the honour of presenting to the Royal Society* an account of 
researches carried on with a view of determining' the effects of stress and strain on the 
O 
elasticity and electrical resistance of metals. Side by side with these researches were 
conducted others on magnetic induction and thermo-electricity, and a very considerable 
amount of experimental detail was collected with reference to the two last physical 
properties of matter. The results of the last-mentioned investigations have, however, 
now remained unpublished for several years, for it seemed desirable that, previously to 
publication, certain phenomena should, if this were possible, have light thrown upon 
them by further experiments on elasticity. More especially was I anxious to examine 
into the causes of the loss of energy experienced by a wire when vibrating torsionally, 
for the interesting memoirs of G. WiedemaNN f and D. E. Hughes led me to expect 
that my doing so would cause some insight to be gained regarding the above-mentioned 
phenomena. The results of these labours, which have now occupied almost the whole 
of my spare time for the last three years, I offer to the Society in the hope that they 
may prove as interesting to others as they are to myself. 
Researches of Thomson and Wiedemann. 
Under the title of “ The Elasticity and Viscosity of Metals,” Sir W. Thomson 
published a memoir,]; the first portion of which deals with the loss of energy of a wire 
* ‘ Phil. Trans.,’ Part 1, 1883. 
t ‘ Wiedemann’s Annalen,’ vol. 6, 1879. 
X 1 Roy. Soc. Proc.,’ vol. 14, 1865, p. 289. 
5 K 
M DCCCLXX XVI. 
